A centralized lock system for an automotive vehicle can have a plurality of vehicle door locks on the respective doors of the vehicle, a central locking unit for controlling the vehicle door locks, a servomotor in each individual door lock and an electrical control and monitoring circuit for actuation and monitoring of the central locking unit. The term "vehicle door" is intended to encompass also the door of the trunk and/or a hood of the vehicle, as well as the filling compartment door or flap which normally conceals the fitting through which fuel is supplied to the vehicle.
The door locks can have, aside from the usual functions, like locking and unlocking, positions providing security against joy riding and vehicle theft. The term "system" is here used in the sense that encompasses a unit whose components are operated in an integrated manner from a central position.
Door locking systems for vehicles are known in a wide variety of constructions as are the door locks which are used therewith. In one locking system over which the invention is deemed to be an improvement, the control and monitoring circuit for the individual control and monitoring functions has separate electrical lines running to the central station from the individual door locks so that a comparatively large number of lines must run to each door lock from the central station and be incorporated into the electrical harness of the vehicle. Mounting of the locks and the wiring of them to the harness can be a time-consuming process.
A lock system of the type with which the invention is concerned is found, for example, in German patent DE 35 26 501 C2 and the corresponding U.S. Pat. No. 4,735,447.
It should be noted that electrical systems with reduced wiring needs utilizing binary busses, multiplexing and the like are described in German patent DE 34 17 956 C2 and German open application DE 41 41 504 A1. However the principles of these latter systems have not, to my knowledge, been hitherto utilized in the field of vehicle lock systems.